The problem of access to research has been well covered in the Guardian - by analysis, by excoriation and by parable. The situation again, in short: governments and charities fund research; academics do the work, write and illustrate the papers, peer-review and edit each others' manuscripts; then they sign copyright over to profiteering corporations who put it behind paywalls and sell research back to the public who funded it and the researchers who created it. In doing so, these corporations make grotesque profits of 32%-42% of revenue - far more than, say, Apple's 24% or Penguin Books' 10%.

So far, so depressing. But what makes this story different from hundreds of other cases of commercial exploitation is that it seems to be headed for a happy ending. That's taken some of us by surprise, because we thought the publishers held all the cards. Academics tend to be conservative, and often favour publishing their work in established paywalled journals rather than newer open access venues.

The missing factor in this equation is the funders. Governments and charitable trusts that pay academics to carry out research naturally want the results to have the greatest possible effect. That means publishing those results openly, free for anyone to use. Suddenly it seems that funding bodies are waking up to the importance of this. In recent weeks, we've seen the Wellcome Trust promising to get tough on grant recipients who don't make their work available; the astonishing pro-open access speech by science minister David Willetts to the Publishers Association AGM; and the European Union's intention to use open access for the results of its €80 billion Horizon 2020 programme.

Publishers' responses to all this have been tiresomely predictable. Commenting on the new draft open-access guidelines proposed by Research Councils UK, Graham Taylor of the Publishers Association said that publishers would not accept that authors could deposit their papers in open-access repositories six months after publication. This is pure bluster. It's none of publishers' business what conditions funders impose on authors. Publishers are only service providers, with no more right to dictate policy than suppliers of laboratory equipment. If funders choose to impose conditions, authors will have to abide by them. If that means depositing papers in open-access repositories, publishers who forbid that will simply be bypassed in favour of those that are not stuck in the 1990s.

So mandates from funders are the way to break through on open access, and it's great to see the UK and European Union leading the way. The surprise at the moment is that the US government - having introduced the important and influential NIH public access policy in 2005 - seems to have fumbled the ball. This is disappointing for the US, but also disturbing for Britain. As Willetts pointed out in his speech: "In future we could be giving our research articles to the world for free via open access. But will we still have to pay for foreign journals and research carried out abroad?" For any country to get the full benefit from its own government's open-access mandates, it needs other countries to do the same.

Happily, an opportunity has arisen in the US to fix this. The White House's Office of Science and Technology Policy has taken a strong interest in open access, sponsoring two requests for public information in as many years. The issue also has the attention of President Obama's science adviser, who has met with both publishers and open access advocates. There is a feeling that the administration fully understands the value of open access, and that a strong demonstration of public concern could be all it takes now to goad it into action before the November election. To that end a Whitehouse.gov petition has been set up urging Obama to "act now to implement open access policies for all federal agencies that fund scientific research". Such policies would bring the US in line with the UK and Europe.

There is always a question of whether petitions really make a difference. But there are good reasons for optimism in this case. The White House has been looking at open access for some time and is known to be sympathetic. This is a chance to demonstrate public support for action, and the executive has the power to direct federal agencies to take that action. Also, there is already bipartisan legislation in both US houses to require public access to federally funded US research. Demonstrating public support will strengthen this legislation's chances. Change in politics comes when the opportunity for decision coincides with a clear statement of the community's view. You need both.

So please sign the White House petition. You do not need to be a US citizen. Anyone aged 13 or older is eligible. Signing requires very minimal registration (email address and password), and clicking a link in a confirmation email. Do it now. You can make a difference.